Updating an existing value in php - php

Question

I'm inserting some values into my database, which is working successfully. However when i insert a new value for an id that has a previous value, the old val isn't replaced by the new, instead they're kept both. I'm trying to update the function with an if/else statement (commented part). But still the same result.
$options = '';
$filter=mysql_query("select afnumber from employees WHERE Status='Employed '");
while($row = mysql_fetch_array($filter)) {
$options .="<option >" . $row['afnumber'] . "</option>";
}
$menu="<form id='filter' name='filter' method='post' action=''>
AFNumber : <select name='SelectAF' id='filter' style='color:grey;'>" . $options . "</select>
Added hours: <input type='text' name='AddedHours' style=' padding: 10px;border: solid 2px #c9c9c9; width:50px; height:2px;'>
<input type='submit' name='submit' value='Submit' style='width:80px; height:30px; text-align:center; padding:0px;'>
</form>
<br>
";
/* if(isset($_POST['submit'])){
$addedhours = $_POST['AddedHours'];
$selectaf = $_POST['SelectAF'];
if($addedhours == ""){
$sql="INSERT INTO `editedworkhours` (`AFNumber`,`AddedWH`) VALUES('$selectaf','$addedhours')";
$getResult =mysql_query($sql);
}
else{
$sql2 = "UPDATE editedworkhours SET AddedWH=$addedhours WHERE AFNumber=$selectaf";
$getResult =mysql_query($sql2);
}
}
echo $menu; */
echo '<div class="scrolldiv">';
try {
$conn = new PDO('mysql:host=localhost;dbname=hr', 'root', 'J546');
$conn->exec("set names utf8");
$conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$num_rows = $conn->query('SELECT COUNT(*) FROM employees')->fetchColumn();
$pages = new Paginator($num_rows,9,array(15,3,6,9,12,25,50,100,250,'All'));
echo $pages->display_pages();
echo "<span class=\"\">".$pages->display_jump_menu().$pages->display_items_per_page()."</span>";
$stmt = $conn->prepare("SELECT employees.afnumber,employees.name,employees.dateofemployment,employees.actualpost,employees.department FROM employees WHERE employees.status='Employed' AND (employees.afnumber LIKE '%$search%' OR employees.name LIKE '%$search%') ORDER BY employees.afnumber DESC LIMIT :start,:end");
$stmt->bindParam(':start', $pages->limit_start, PDO::PARAM_INT);
$stmt->bindParam(':end', $pages->limit_end, PDO::PARAM_INT);
$stmt->execute();
$result = $stmt->fetchAll();
$ewhtable = "<table class='sortable'><tr><th>AFNumber</th><th>Employee Name</th><th>Years of Service</th><th>Actual Post</th><th>Department</th><th>Added Hours</th></tr>\n";
foreach($result as $row) {
$years=explode("/", $row[2]);
$years[2]=intval(date ('Y')) - $years[2];
$sql="SELECT addedwh FROM editedworkhours WHERE afnumber='$row[0]'";
$var = "";
$stmt = $conn->prepare($sql);
$stmt->execute();
$result2 = $stmt->fetchAll();
foreach ($result2 AS $row2) {
$var .= $row2['addedwh'] . "\n";
}
$ewhtable .= "<tr><td>$row[0]</td><td>$row[1]</td><td>$years[2]</td><td>$row[3]</td><td>$row[4]</td><td>$var</td></tr>\n";
}
$ewhtable .= "</table>\n";
echo $ewhtable;
exportTable(str_replace("&","",$ewhtable),"EmployeeWorkingHoursTable");
echo $pages->display_pages();
echo "<p class=\"paginate\">Page: $pages->current_page of $pages->num_pages</p>\n";
echo "</div>";
} catch(PDOException $e) {
echo 'ERROR: ' . $e->getMessage();
}

Answer 1

If AddedHours input value has only a space, your comparison if($addedhours == "") will fail.
Always trim the values before comparison.
$addedhours = trim($_POST['AddedHours']);